A known technique for ejecting a liquid material in the form of flying droplets employs a retracting and advancing plunger. The plunger is quickly accelerated to advance and then abruptly stopped by abutting it against a valve seat. Upon the abrupt stop, an inertial force is applied to the liquid material present in front of the plunger, thus causing the liquid material to eject in the form of flying droplets under the action of the inertial force.